Re: VIRL Routing Issue

Thanks for the additional information which I believe does help us identify the problem. The outputs are consistent with having ip routing enabled. And significantly there is this message

Gateway of last resort is not set

You may be thinking that you did configure the gateway using this command which is in the partial config that you posted

ip default-gateway 10.1.1.254

So if the config does have the default-gateway configured why is it not working? The answer is that default-gateway is intended for switches operating as layer 2 switches. When you configure "ip routing" then the switch operates as a layer 3 switch and will ignore the default-gateway command.

So there are 2 ways to fix this problem. You can leave ip routing enabled and configure a static default route with the router interface address as the next hop (ip route 0.0.0.0 0.0.0.0 <routerIP>) or you can remove ip routing and let the configured default-gateway work. Either solution should work. I would agree with your comment that it seems to make more sense to have the switches be layer 2 and to have the routing done on the router.

Re: VIRL Routing Issue

Rick,

Thank you for all of your help. Your explanation definitely makes sense and got us to the solution but I think it did require one very specific detail that should be mentioned for anyone who may have issues in the future.

IP route was the issue but it was because in VIRL you MUST explicitly tell the switch "no ip routing" otherwise, even if it is not configured with "ip routing" it seems to still cause the issues you helped work out.

Thank you again for all of your help and I will mark your post as the solution!

Re: VIRL Routing ISsue

The main thing I notice so far is that on both of the edge switches the G0/2 is an access port and no vlan is specified. The result is that both of these interfaces are in vlan 1. Your switch configs and your trunks do not do anything with vlan 1. Your first step should be to configure the G0/2 interfaces to assign them to the appropriate vlans (10 and 20).

Re: VIRL Routing Issue

So, Int G0/2 on the edge switches don't actually have any thing connected to those ports. I also should have been clear on what I was trying to do, so let me fix that.

I set up the network with Switches 1 and 2 as the VLAN 10 network and 3 and 4 as the VLAN 20 network. All I want to do is have a simple lab where I have routing between the two networks. As you can see in the configs I posted I have the router performing routing using EIGRP with the two networks set. I just want to be able to ping between the "Core" Switches (Sw 1, and Sw 3). With this same design on PacketTracer, I have no issue. For some reason I cannot, for the life of me, get this to work on VIRL (But I digress). So, that is all I am really trying to do. The switches should be able to communicate between themselves without an edge device (I can't exactly through in a host machine without it being a server from my understanding).

Re: VIRL Routing Issue

Thanks for the additional information. For the moment I believe that we can concentrate on switch 1 and 3 and the router. If we figure out the issue with them then most likely we will have solved the issue for switch 2 and 4.

Re: VIRL Routing Issue

Tyler

Thank you for the outputs. What I am seeing in them is pretty much what I expected to see. The router sees both switches as neighbors (and on the correct interface - I have seen situations where the cables were not connected on correct interface and that does create problems - but not the case here). The arp table on the router shows entries for both switches. The router interfaces are up/up. The switches see the router as a neighbor and their arp table shows entries for the router. Based on that I would expect that both switches should be able to communicate with the router and that both switches should be able to communicate with each other. If that is not happening then I believe that there must be something in the parts of the configs that we have not seen that is creating the problem.

Can you clarify for me what is the problem? Can each switch ping the connected interface of the router? Can each switch ping the router interface connecting to the other switch? Can each switch ping the vlan interface of the other switch?

In thinking about what might be the issue I wonder if ip routing is enabled on the switches? Can you post the output of show ip route for both switches?

Re: VIRL Routing Issue

Rick,

Yes the problem is that neither side of the network can ping or communicate with the other even with the router configured. Switch one cannot ping the interface of the router going to the opposite network or any switch in that network. This is also true for Switch 3 (excluding switch 2 and 4 from this for the time being but all statements are also true for these). Each switch can ping the router interface of their respective network.

Wouldn't IP routing only be needed if the switches were not going to be layer 2 switches? shouldn't the router be doing all of the routing with the switches passing their traffic using the ip default-gateway x.x.x.x command. Maybe I have something wrong here?

Re: VIRL Routing Issue

Thanks for the additional information which I believe does help us identify the problem. The outputs are consistent with having ip routing enabled. And significantly there is this message

Gateway of last resort is not set

You may be thinking that you did configure the gateway using this command which is in the partial config that you posted

ip default-gateway 10.1.1.254

So if the config does have the default-gateway configured why is it not working? The answer is that default-gateway is intended for switches operating as layer 2 switches. When you configure "ip routing" then the switch operates as a layer 3 switch and will ignore the default-gateway command.

So there are 2 ways to fix this problem. You can leave ip routing enabled and configure a static default route with the router interface address as the next hop (ip route 0.0.0.0 0.0.0.0 <routerIP>) or you can remove ip routing and let the configured default-gateway work. Either solution should work. I would agree with your comment that it seems to make more sense to have the switches be layer 2 and to have the routing done on the router.

Re: VIRL Routing Issue

Rick,

Thank you for all of your help. Your explanation definitely makes sense and got us to the solution but I think it did require one very specific detail that should be mentioned for anyone who may have issues in the future.

IP route was the issue but it was because in VIRL you MUST explicitly tell the switch "no ip routing" otherwise, even if it is not configured with "ip routing" it seems to still cause the issues you helped work out.

Thank you again for all of your help and I will mark your post as the solution!

Re: VIRL Routing Issue

Tyler

Thanks for the update. Glad you got it worked out. It is very interesting that this is a behavior of VIRL and I suspect quite a few in the community were not aware of this. Thank you for marking this question as solved. This will help other participants in the community to identify discussions which have helpful information. This community is an excellent place to ask questions and to learn about networking. I hope to see you continue to be active in the community.

We are having issues with a WS-C2960X-48FPD-L running IOS 15.2(2)E7. Some ports are simply not working. We had POE issues on some of the ports and decided to upgrade to hopefully resolve those issues but this has now become an even bigger issu...
view more

the scenario is :I'm replacing core Cisco switch 4506-E with switch 4507R-E. As I have one supervisor card on 4506-E and I'm going to take out all the card that I have in 4506-E and install it in the new 4507R-E. On the 4507R-E I have 2 slots for the supe...
view more

Since its release in August of 2019, the SASE report released by Gartner has generated a lot of chatter regarding what SASE is all about. People are wondering whether it will be disruptive to the current network and network security designs and are curiou...
view more

I tried to setup a virtual environment with 2960 switches and 2911 Router. In one part of the network where I connected PCs directly to the 2911 Router, I was able to communicate to the attached devices, having configured static route. In the th...
view more